Why your brain needs the “Just Right” Stress to Thrive.

Recently, while encouraging my children to try something difficult, I was reminded of a truth I see in every part of my work. Growth comes from doing hard things. Not from ease, but from stretch, uncertainty and gentle pressure. And it struck me how often we forget this as adults. Our nervous system still learns through challenge. We still gain capability from the right kinds of stress.

As a nurse and mental fitness coach, I see this play out daily. People grow at the edges. Not in the comfortable moments, but in the moments where we are stretched, supported and slightly unsure. The moments where a part of us whispers, “Can I really do this?”

Growth is not endless pushing or grinding. It is the ability to move in and out of comfort, stretch, growth and rest. This idea is well supported in resilience research, including Paul Taylor’s work on hardiness and adaptive stress exposure (Taylor, 2024), and aligns closely with Nassim Taleb’s concept of antifragility, where systems become stronger through well-measured challenge, not despite it (Taleb, 2012).

The Goldilocks Principle: Finding the Sweet Spot

One of the most useful ways to understand stress is through the Goldilocks Principle. This is also reflected in the Yerkes–Dodson Law, a long-standing model in psychology showing how performance increases with arousal up to a point before declining again (ASME Medical Education Review).

Too little stress
• low performance
• boredom or apathy
• reduced capability

Just enough stress
• highest performance
• focus, learning and energy
• growth through hormesis

Too much stress
• overwhelm or anxiety
• errors
• burnout and fragility

The right amount of stress strengthens us. The wrong amount overwhelms us.

The Window of Tolerance: Where Growth Happens

The Window of Tolerance, a concept developed by Dr Dan Siegel (1999), explains our psychological capacity for stress.

Inside the window
• emotions are manageable
• thinking is clear
• problem solving is possible
• learning and growth can occur

Outside the window
• hyper-arousal
• hypo-arousal

Recognising where we are on this spectrum keeps us anchored in the zone where stress becomes strengthening rather than harmful.

Why Stress Matters

Stress is not the enemy. It is information.
It signals that something meaningful is happening. It mobilises energy, focus and adaptation.

In healthcare and coaching settings I see how:
• too little stress stalls progress
• too much stress overwhelms
• the right amount transforms capability

This reflects the well-established principle of hormetic stress: small, controlled doses build capacity over time (Taylor, 2024).

How Stress Shows Up

Stress does not always look dramatic. It often arrives quietly as:
• mental fog
• irritability
• tension in the body
• emotional sensitivity
• hesitation or avoidance
• loss of confidence

These are not signs of weakness. They are signs of activation. They tell us to pay attention.

Comfort, Stretch, Growth and Overwhelm

We continually move between:
• Comfort Zone
• Stretch Zone
• Growth Zone
• Overwhelm

Mental fitness is the skill of noticing which zone we are in and adjusting. Growth is what develops when we repeat this cycle over time. This mirrors the adaptive stress-response models used in resilience science and trauma-informed practice (Levine, 2010).

When We Push Too Hard: Resetting the System

Overshooting into overwhelm is normal. What matters is how we return.

Notice, Name, Neutralise
• Notice what you feel
• Name the emotion
• Neutralise it by reminding yourself it is a signal, not a threat

This brings the thinking brain back online, a principle supported in both neuropsychology and somatic therapies.

Breathwork
A slow exhale lowers arousal and restores clarity.

Nature exposure
Green and blue spaces calm the nervous system.

Micro-rest and micro-recovery
Small intentional pauses prevent burnout.

Compassionate return
Rest is not the opposite of growth. Rest is part of growth.

How This Applies to Adults, Professionals and Teams

Whether we are navigating complex workloads, adapting to change, stepping into leadership or rebuilding confidence after stress, the principle is the same. Capability grows through small, safe stretches. The same pattern that strengthens individuals also strengthens teams.

In my clinical and coaching work, I use questions that restore autonomy and invite growth:
• What feels manageable today
• What small step would move you forward
• What choice aligns with who you want to be in this moment
• If you were to act today, what would that look like

When these questions become part of a team culture, psychological safety increases. People feel seen, supported and able to take risks. Mistakes become learning. Curiosity grows. Challenge becomes balanced rather than overwhelming.

Teams, like individuals, grow through consistent stretch moments, not ongoing pressure.

The Power of Small Wins

Confidence is created through evidence.
Every small success expands the Window of Tolerance and widens our capacity.

Each win shifts identity from “I can’t” to “I can.”
That shift changes everything.

Why This Matters

Growth is a rhythm: challenge, rest, integrate, repeat.

If we want to build capability, resilience and mental fitness, we need to cultivate:
• courage to begin
• willingness to stretch
• awareness to pause
• compassion to rest
• belief in the next small step

Growth is not loud or dramatic. It is the steady choice to lean forward, listen to ourselves and continue.

Forget fear. Growth is the daily choice to stretch gently and intentionally. That choice changes everything.

Call to Action

Where is your “just right” level of stretch today?
What is one small, manageable challenge you can lean into this week?
Share it below or reach out if you’d like guidance in building resilience, mental fitness and sustainable capability.

References

• Taylor, P. (2024). The Hardiness Effect: Building Resilience Through Adaptive Stress.
• Taleb, N. N. (2012). Antifragile: Things That Gain from Disorder. Random House.
• Siegel, D. (1999). The Developing Mind: How Relationships and the Brain Interact to Shape Who We Are. Guilford Press.
• Levine, P. (2010). In an Unspoken Voice: How the Body Releases Trauma and Restores Goodness.
• ASME Medical Education Review on the Yerkes–Dodson Law and performance–arousal relationships.